Seismic signal from recent Martian impact detected by InSight?
According to a science paper released today, a small impact that occurred about 25 miles south from the InSight lander between February 21st and April 6, 2019 might have been detected by the spacecraft’s seismometer.
From the paper’s abstract:
During this time period, three seismic events were identified in InSight data. We derive expected seismic signal characteristics and use them to evaluate each of the seismic events. However, none of them can definitively be associated with this source. Atmospheric perturbations are generally expected to be generated during impacts; however, in this case, no signal could be identified as related to the known impact. Using scaling relationships based on the terrestrial and lunar analogs and numerical modeling, we predict the amplitude, peak frequency, and duration of the seismic signal that would have emanated from this impact. The predicted amplitude falls near the lowest levels of the measured seismometer noise for the predicted frequency. Hence it is not surprising this impact event was not positively identified in the seismic data.
Based on this data, they now think they will only be able to detect about two impacts per year with InSight’s seismometer, a decrease from the previous estimate of as many as ten.
According to a science paper released today, a small impact that occurred about 25 miles south from the InSight lander between February 21st and April 6, 2019 might have been detected by the spacecraft’s seismometer.
From the paper’s abstract:
During this time period, three seismic events were identified in InSight data. We derive expected seismic signal characteristics and use them to evaluate each of the seismic events. However, none of them can definitively be associated with this source. Atmospheric perturbations are generally expected to be generated during impacts; however, in this case, no signal could be identified as related to the known impact. Using scaling relationships based on the terrestrial and lunar analogs and numerical modeling, we predict the amplitude, peak frequency, and duration of the seismic signal that would have emanated from this impact. The predicted amplitude falls near the lowest levels of the measured seismometer noise for the predicted frequency. Hence it is not surprising this impact event was not positively identified in the seismic data.
Based on this data, they now think they will only be able to detect about two impacts per year with InSight’s seismometer, a decrease from the previous estimate of as many as ten.